At first glance, the idea of making phone calls via the Internet seems like adding a layer of complication to something that has been perfectly simple to do for decades.
Unbeknown to us, many phone companies as well as corporate phone customers often use the Internet to transmit our voices already, and the technology is moving so fast that it is fair to say it is growing by the week.
The buzz word is VoIP, meaning "Voice over Internet Protocol" and pronounced vee-oh-eye-pee. It is likely to be all over the CeBIT electronics trade fair beginning in Germany on Thursday and running till March 15.
VoIP has been making major headway in places where access to the phone system is metered by the minute, but access to the Internet is paid for by the month at a so-called flat rate, meaning the customer can use as much of the Internet as they like.
It's easy to see why this makes phone calls via the Internet attractive, especially if you make a lot of international calls.
Since you are paying the flat rate anyway, the VoIP calls are effectively free.
Internet telephony has been around for a few years, but it had a rocky start because the early connections were terrible. Sometimes they sounded fine, but often the sound was distorted, only snatches came through or the connection would crash completely.
A bold Internet start-up called Skype changed all that. Millions of people have signed up for free accounts with Skype and are chatting over its lines. All you need is a computer and a headset that contains headphones and a microphone.
The rest of the wave has come with VoIP phones, which look like conventional phones but are sold by Internet service providers.
You don't need to have your computer switched on: These new-fangled phones take care of it all, sending the signals through broadband connections such as DSL or the TV cable, and the customer pays just a single Internet fee.
Just how far VoIP has come is hard to judge, especially since many of us may not even realize that calls at the office, for example, are being routed via the Internet.
The call quality today is generally as good as with mobile phones, though an echo on the line or an unusually long delay when another person replies to what you say are clues that an Internet connection is in use.
"The delay can be quite annoying because you keep interrupting one another and starting to talk again," says Jochen Noelle, a German who operates a Web site devoted to the topic, VoIP-Info.de. Noelle says you soon get used to it.
The main losers are traditional telephone companies that have earned a living by charging for phone use by the minute.
The British business magazine the Economist recently had a cover story showing a desert with a bleak line of broken telephone polls and the line, "How the Internet broke the phone business."
For corporate customers, a major attraction is that phone and Internet services do not have to be purchased separately. Most businesses already have the personal computers in place. With one mouse click, staff can place phone calls.
Germany is now moving to the next big thing: Individuals can obtain a single "phone number" that will be the destination for all calls whether they are at home or using a mobile, for faxes and for e-mails.
The service in Germany is code-named ENUM, which stands for Eine Nummer (the one number).